Agate Bay Stormwater Improvements Phase I

Update October 8-12, 2018

The heavy lifting is done for the Agate Bay Stormwater Improvements – Phase I project, as the remaining two filter vaults have been installed. The first is located on North Shore Rd. near Agate Heights Rd., where a pretreatment structure was installed upstream of the vault. The other is located near the intersection of Agate Heights Rd and Topaz Ct., where an existing stormwater detention pond provides pretreatment. All excavated areas have been backfilled and hydro-seeded, where necessary.

An asphalt curb was placed along a short portion of Agate Heights Rd. near North Shore Rd., in order to direct stormwater toward a catch basin and prevent it from flowing onto the roadway. Fresh asphalt has been placed where there were road cuts and striping is complete. Minor work will take place in the coming weeks, including tasks such as swapping out catch basin lids, grouting, and landscaping. Most importantly, all of the structures are ready to receive stormwater and provide treatment as the rain returns this fall.

Update July 23-27, 2018

The Agate Bay Stormwater Improvements – Phase I project is well under way. Colacurcio Brothers, Inc. has been busy installing check dams and rock armoring within ditches along the east side of Agate Heights Road, in order to reduce stormwater runoff flow rate and prevent erosion. An existing pipe on the west side of Agate Heights Road, near Northshore Drive, was removed due to its poor condition. It was replaced with a new pipe and two additional catch basins, which will help remove sediment that is moving through the system.

Work has also been performed at the North Shore location, just west of Agate Bay Lane. New catch basins and storm mains are being installed to replace the failing, existing structures in this area. A filter vault is being installed as a part of these upgrades, which will provide treatment to stormwater before it discharges into Lake Whatcom. Work at this location will continue into this week.

Capital Improvement Project Information Sheet

Title: Agate Bay Stormwater Improvements Phase I

Contact information: Kraig Olason, Project Manager, Whatcom County Public Works Stormwater Division
Phone: 360-778-6301 Email: [email protected]

Location: The Agate Bay Stormwater Improvements Phase I project will take place on Agate Heights Road and Northshore Road between Agate Heights Road and Agate Bay Lane, approximately 2.2 miles east of Bellingham City Limits on Northshore Road (Township 38 North, Range 3 East, Sections 24-25)

Problem Statement: Lake Whatcom provides a drinking water source, a place to recreate, and provides aquatic habitat for many species, making it a vital resource for the residents of Whatcom County. Due to an increase in algal blooms and a decline in water quality, protecting this resource has become a top priority. During rain events, phosphorous and other pollutants that impact water quality are carried into the lake through stormwater conveyance systems. Sediment is a common source of phosphorous, but can also carry pollutants such as metals and pesticides.

Agate Bay has been identified as a location within the watershed that is contributing to the phosphorous loading issue. This is a result of increased development and impervious surfaces, which causes water to move quickly over the land's surface rather than infiltrating into the soil. Unstable roadside ditches in this area also contribute sediment that is transported to Lake Whatcom during rain events.

In addition to water quality concerns, a location has been identified on Agate Heights Road, near Northshore Road, where excess stormwater has been sheeting across the road, causing icy conditions during winter weather.

Project Description: This project addresses stormwater pollutants impacting Lake Whatcom by stabilizing ditches, installing check dams to slow flow and improve infiltration, and installing three filter vaults that target phosphorous reduction. Additionally, upgrades to existing storm drainage infrastructure will help address stormwater conveyance and safety issues.

Project Goals:

Reduce phosphorous by treating stormwater runoff before it discharges into Lake Whatcom.
Prevent erosion, slow down flow during heavy rain events, and encourage infiltration.
Upgrade conveyance systems with safeguards for large storm events and improve safety.

Project Duration and Schedule: Work will begin on July 9th, 2018 and will take an estimated 8 weeks to complete. Working hours for this project are 7:00 am to 5:30 pm.

For more information, please see the current Press Release 7/11/18

Press Release 7/6/18